Cinnamon Do Not Disturb and Update Manager Notification Interoperability

Goal: Ensure that Linux Mint's Update Manager suppresses its update notifications when Cinnamon's Do Not Disturb mode is active, preventing interruptions during presentations or full‑screen work.

Constraint: The Update Manager preferences expose only automatic check frequency and update type filters; there is no visible option to query or honor the DND state, and it is unclear whether this behavior is a configurable oversight or a limitation of the underlying notification daemon.

Questions: Does Update Manager provide a hidden setting or DBus interface to respect Cinnamon's Do Not Disturb flag? Can a system‑wide notification rule be created to suppress Update Manager alerts based on the DND state? Does this behavior differ between Linux Mint 21.3 (Cinnamon 5.8) and Linux Mint 22.0 (Cinnamon 6.0)?